Weighing system for weighing railroad cars and their load

Abstract

A system for weighing railroad cars and their load is disclosed. In virtually all railroad cars, there exists a disk on a bottom of a railroad car that fits or interfaces with a well in a wheel truck assembly at each end of the railroad car. A load cell is constructed having one surface to bear against the bottom of the disk on the railroad car, and an opposite surface for bearing against a bottom surface of the well in the wheel truck assembly. The output of the load cell is provided to a telemetry transmitter, which transmits an indication of weight to an operator of a crane or other loading appartus loading the railroad car.

Having thus described my invention and the manner of its use, it should be apparent that incidental changes may be made thereto that fairly fall within the following appended claims, wherein I claim:  
     
       1. A weighing system for a railroad car comprising; 
       a railroad car further comprising;  
       at least a first wheel truck assembly located at one end of said railroad car and a second wheel truck assembly located at an opposite end of said railroad car,  
       an interface between said railroad car and each said wheel truck assembly, said interface comprising at least a disk having a bottom surface, the disk mounted to said railroad car and a well in each said wheel truck assembly for receiving said disk, and for each said interface, said weighing system comprising;  
       a ring fitted about a periphery of said disk,  
       a load cell in a lower region of said ring, with an upper surface of said load cell bearing against said bottom surface of said disk, said load cell extending below said lower region of said ring so that said load cell rotatably fits in said well, with a lower surface of said load cell bearing against a bottom of said well,  
       whereby as said railroad car is loaded, said upper surface of said load cell and said lower surface of said load cell are displaced with respect to each other, developing an electrical output representative of weight.  
     
     
       2. A weighing system as set forth in  claim 1  wherein said upper surface of said load cell that bears against said bottom surface of said disk is along an upper rim of said load cell and said lower surface of said load cell that bears against said bottom of said well is a center region of said load cell. 
     
     
       3. A weighing system as set forth in  claim 1  wherein said load cell is a separate component from said ring, and said load cell is mounted in said ring so as to allow vertical movement of said load cell with respect to said ring while said load cell is restrained from rotational and lateral movement within said ring. 
     
     
       4. A weighing system as set forth in  claim 1  further comprising a pin extending through a center region of said well, said pin having a threaded region on an upper end thereof, and a mating threaded opening in a central region of said load cell for receiving said threaded region of said pin, said pin further including a flange that bears against said lower surface of said load cell. 
     
     
       5. A weighing system as set forth in  claim 4  further comprising a hardened wear and load distribution plate fitted within said well, with a lower surface of said flange bearing against said wear and load distribution plate. 
     
     
       6. A weighing system as set forth in  claim 1  wherein displacement between said upper surface and said lower surface is limited to prevent damage to said load cell. 
     
     
       7. A weighing system as set forth in  claim 1  wherein said load cell is provided with a plurality of openings between said upper surface and said lower surface, with web regions between said openings, and at least one strain gage mounted to at least one said web region of each said opening so as to provide an electrical signal that varies directly with flexure of said web region. 
     
     
       8. A weighing system as set forth in  claim 7  further comprising a pair of said strain gages mounted in each said opening, each said strain gage of said pair of strain gages in each said opening mounted to respective said web regions of a respective said opening, each said strain gage further centered on a line defining a closest point between said openings so that impedance of one strain gage of said pair of strain gages increases and impedance of the other strain gage of said pair of strain gages decreases with load applied to the load cell. 
     
     
       9. A weighing system as set forth in  claim 8  wherein said strain gages are coupled in a bridge circuit having four legs, with four strain gages in each said leg of said bridge circuit. 
     
     
       10. A weighing circuit as set forth in  claim 9  wherein each said leg comprises two strain gages coupled in series to form a series pair, with two of said series pairs coupled in parallel to form said leg of said bridge circuit. 
     
     
       11. A weighing system as set forth in  claim 9  wherein output signals from a first load cell at one end of said railroad car and output signals from a second load cell at an opposite end of said railroad car are summed to provide a summed signal indicative of weight of said railroad car and load therein, and a radio transmitter that receives said summed signal and transmits a radio signal containing said summed signal to a remote location. 
     
     
       12. A weighing system for measuring weight of a railroad car and a load therein with a relatively high degree of accuracy, said railroad car having a disk mounted to a load-bearing region of a bottom of each end of the railroad car and a wheel truck assembly positioned at each said end of the railroad car, each said wheel truck assembly provided with a centrally located recess in an upper surface thereof for rotatably receiving a respective said disk, said weighing system comprising; 
       a combined weight scale and load interface positioned between said disk on said railroad car and said recess in said wheel truck assembly, said weight scale and load interface comprising:  
       a mounting ring for each said disk, said mounting ring fixedly mounted about a periphery of said disk so that a lower edge of said mounting ring extends below said disk,  
       a load cell generally fixed within each said mounting ring, said load cell having an upper annular surface adjacent to a peripheral region constructed to closely fit within said ring, with said upper annular surface adapted to bear against a lower surface of said disk and against sides of said recess, laterally and rotatably connecting said railroad car and said wheel truck assembly, said load cell further having a lower central region fitted in a respective said recess so that shear displacement between said peripheral region and said central region is sensed and an electrical signal provided that is indicative of weight applied to that said load cell,  
       a load bearing portion in coaxial relation with said central region, and fitted in said recess for distributing coaxial loads from said central region into said recess.  
     
     
       13. A weighing system as set forth in  claim 12  wherein said load bearing portion further comprises a pin engaging a coaxial opening in said central region of said load cell, and extending at an opposite end into an opening coaxially located in said well. 
     
     
       14. A weighing system as set forth in  claim 13  further comprising a hardened, weight distributing plate on a floor of said well and a flange fixed to said pin, said flange bearing between said central region of said load cell and said weight distributing plate. 
     
     
       15. A weighing system as set forth in  claim 14  wherein said electrical signal from each said load cell is summed in order to develop a composite electrical signal indicative of total weight of said railroad car and its load. 
     
     
       16. A weighing system as set forth in  claim 12  wherein said shear displacement occurs in a plurality of thick webs between said peripheral region and said central region, said plurality of thick webs permitting a displacement of about 0.010 inches between said peripheral region and said central region under a load of about 200,000 pounds. 
     
     
       17. A weighing system as set forth in  claim 15  wherein said composite electrical signal is provided to a radio transmitter for wirelessly transmitting said composite electrical signal to a receiver at a remote location. 
     
     
       18. A method for fitting a railroad car and each wheel truck assembly associated therewith with weight sensing and load-transmitting apparatus for indicating weight of the railroad car and load therein while securely interfacing each said wheel truck assembly to said railroad car, said weight sensing and load-transmitting apparatus indicating weight to a resolution of about 500 pounds or so, and said railroad car having a load-transmitting disk at each end thereof for each said wheel truck assembly and a well in each said wheel truck assembly into which said disk is rotatably fitted, said method comprising the steps of: 
       positioning a first load bearing member to bear on a lower surface of said disk and against side surfaces of said well,  
       laterally restraining said first load bearing member with respect to said disk,  
       positioning a second load bearing member to bear on a bottom surface of said well, said first load bearing member and said second load bearing member connected so that weight applied to said first load bearing member and said second load bearing member causes deflection, in direct relation with said weight, to occur between said first load bearing member and said second load bearing member,  
       developing an electrical signal from said deflection indicative of said weight,  
       summing said electrical signal from each said weight-sensing and load transmitting apparatus to develop a weight signal indicative of total weight of said railroad car and its load.  
     
     
       19. A method as set forth in  claim 18  further comprising the step of positioning one end of a pin coaxially in said second member, and placing an opposite end of said pin in an opening coaxially located in said well. 
     
     
       20. A method as set forth in  claim 19  further comprising the step of constructing a flange on said pin, and positioning a load plate on a floor of said well, said flange bearing between said load plate and said second member.